Video said to show moment of explosion

‘Intentional’ act

New York mayor Bill de Blasio said he believed that the explosion was “intentional” but that there was no immediate evidence of a link to terrorism.

“I want to say more broadly there is no specific and credible threat against New York City at this point in time from any terror organization,” he told the press.

“So as we are analyzing what happened here we are doing it against the backdrop but we have no credible or specific threat at this moment. But we do want to be very clear: the early indications, the initial indications is this was an intentional act.”

The blast, described by one person as “deafening,” happened outside the Associated Blind Housing facility at 135 W. 23rd Street. It provides housing, training and other services for the blind.

Following Saturday evening’s blast, reports emerged of a second explosive device, discovered four blocks away. Local media, citing officials in New York say the police found a pressure cooker connected to a mobile phone with wires attached.

‘It blew the back window out’

Hundreds of people were seen fleeing down the street on a cool evening, as police cordoned off the area.

“It was really loud, it hurt my eardrums. My 10-year-old boy was sat in the back seat of the car, and the explosion blew the back window out,” said Tsi Tsi Mallett, who was in a vehicle driving along 23rd Street when the explosion happened. Her son was not injured.